Reducing paper use actually kills trees. Whenever logging companies cut down a tree, they are required to plant 2-3 trees in it's place. So if you really want to save trees, the best course of action is to use as much paper as possible.

There are actually more trees now then there was 100 or 200 years ago. Shortage of trees is not an issue at all.

Trees produce very little of the oxygen that we breath. The vast majority of it comes from algae.

Putting air hand dryers in bathrooms is actually worse for the environment than using paper towels. Paper is a renewable resource, but hand dryers use electricity, most of which is produced by coal power plants.

Electric cars are not any better for the environment. You charge them with electricity that comes from a coal power plant.

Every living thing and everything that was ever living is a GMO. We have modified all of our crops in order to receive more yield and to make them easier to harvest. Farm animals have been modified to carry more meat. The GMO label means absolutely nothing.

Gluten is only bad for you if you are allergic to it. There is absolutely no benefit to eating gluten free food if you don't have celiac's disease. It is the same as eating dairy free food when you aren't lactose intolerant.

There is no such thing as "wasting water" there is the same amount of water on the Earth as there has always been. It doesn't disappear from the Earth when it goes down the drain. And me not using water, wouldn't cause it to magically appear in the cup of some thirsty African child. The reason there are people who don't have water, is not because there isn't enough fresh water in the world, it is because it is too far away and it is not cost efficient to transport it to where it is needed. When you are "wasting water" you are actually just wasting the energy which is needed to clean and transport the water.

Recycling is not good for the environment. It is an extremely inefficient process that requires someone to drive around a big diesel vehicle and collect the recycling bins from everyones house, take it back to a factory, and then process it back into useable materials. For renewable things like paper, and biodegradable things that can be put into landfills, this process is a complete waste of time and energy.

Overpopulation is not an issue. The entire world's population could fit into a country the size of brazil. And all first world countries throw away more than enough leftover food to feed everyone. Demographers are more concerned about underpopulation in the future with the rise of contraception and abortion as well as the rising popularity of homosexuality.

Global warming is a thing, but is ineptly-named. It doesn't actually increase the Earth's average temperature, but rather increases extremes in temperature, both hot and cold. Resulting in colder winters and hotter summers. And it is such a minor phenomenon that there is really no point in talking about it, because the hot/cold cycles that the Earth goes through have a much greater effect over the Earth's temperature. 2015 studies found that there is actually more ice frozen in the ice caps than ever before.